Export simple .fbx animation to Destinations VR
After 2 days I managed to graps some of the inner working :


There is no problem having multiple separated objects linked to the
same armature 
When importing from blender's .fbx, uncheck the
"convert units to inches from :" checkbox
In the mesh, uncheck "skin parented objects" and check "skin parented transforms"
Never EVER let anything like : suns, lights or cameras when exporting to .fbx
Don't bother painting materials in blender, I
didn't manage to export them to Destinations, just assign names and
build them in hammer


I managed to import a 1000+ part .obj in blender, rigged it with 18 bones with three pistons kinematics, and imported four 120 frame animations with ease respecting those five points.

You can find Here the simple piston that I rigged to test the import.

Bottom line is: to work with destinations VR you need to learn how to rig.